Question

Expand (x-2)^7 using binomial theorem​

Answer 1

x^7-14x^6+84x^5-280x⁴+560x³-672x²+256x-128

Explanation:

7C0•x^7+7C1•x^6•-2+7C2•x^5(-2)²+7C3•x⁴(-2)³+7C4•x³(-2)⁴+7C5•x²(-2)^5+7C6•x(-2)^6+7C7(-2)^7

=>x^7+7x^6(-2)+21x^5(4)+35x⁴(-8)+35x³(16)+21x²(-32)+7x(64)-128

=>x^7-14x^6+84x^5-280x⁴+560x³-672x²+256x-128